diff --git a/control b/control
index d94df0e0ecff88bc9606add4236c00b89b822233..b5fe175590deae8fbb9a372ec0c2c6d9229df28d 100644
--- a/control
+++ b/control
@@ -85,7 +85,7 @@ Build-Depends: autoconf,
                libgstreamer-plugins-base1.0-dev,
                libgstreamer1.0-dev,
                libgtk-3-dev (>= 3.20.0),
-               libharfbuzz-dev (>= 0.9.42),
+               libharfbuzz-dev (>= 2.1.0),
                libhsqldb1.8.0-java (>> 1.8.0.10) [!hppa !mips64 !s390 !sparc] <!nojava>,
                libhunspell-dev (>= 1.1.5-2),
                libhyphen-dev (>= 2.4),
@@ -122,7 +122,7 @@ Build-Depends: autoconf,
                libpagemaker-dev,
                libpagemaker-dev (<< 0.1~),
                libpentaho-reporting-flow-engine-java (>= 0.9.4) [!hppa !mips64 !s390 !sparc] <!nojava>,
-               libpng-dev,
+               libpng-dev (>= 1.6),
                libpoppler-cpp-dev,
                libpoppler-dev (>= 0.14.0),
                libpoppler-private-dev,
diff --git a/rules b/rules
index 956c1935c330bd60928316677dd865053a0e8428..9f43b7848f88fd4c2257cd124e3f5293aba49ef9 100755
--- a/rules
+++ b/rules
@@ -845,7 +845,7 @@ ifneq (,$(filter graphite, $(SYSTEM_STUFF)))
 endif
 
 ifneq (,$(filter harfbuzz, $(SYSTEM_STUFF)))
-	BUILD_DEPS += , libharfbuzz-dev (>= 0.9.42)
+	BUILD_DEPS += , libharfbuzz-dev (>= 2.1.0)
 endif
 
 ifneq (,$(filter libexttextcat, $(SYSTEM_STUFF)))
@@ -886,7 +886,7 @@ ifneq (,$(filter sane, $(SYSTEM_STUFF)))
        BUILD_DEPS += , libsane-dev
 endif
 ifneq (,$(filter libpng, $(SYSTEM_STUFF)))
-       BUILD_DEPS += , libpng-dev
+       BUILD_DEPS += , libpng-dev (>= 1.6)
 endif
 
 ifeq "$(ENABLE_CURL)" "y"
diff --git a/source/lintian-overrides b/source/lintian-overrides
index ce188ad2c79bd0f4c644b4c2db070e59d4ffadd6..90b8bc30be170fd7e7b398eb95808c298c61156d 100644
--- a/source/lintian-overrides
+++ b/source/lintian-overrides
@@ -4,7 +4,7 @@ libreoffice source: source-is-missing [odk/docs/tools.html]
 libreoffice source: source-is-missing [odk/examples/DevelopersGuide/examples.html]
 libreoffice source: source-is-missing [odk/examples/examples.html]
 libreoffice source: source-is-missing [odk/index_online.html]
-# similar, this is NOT minified. FIXME: use node-prismjs even though it's 1.26 while this is 1.28?
+# similar, this is NOT minified.
 libreoffice source: source-is-missing [helpcontent2/help3xsl/prism.js]
 # no, it isn't. the one is always, the other is for tests (<!nocheck>)!
 libreoffice source: redundant-build-prerequisites libmwaw-dev (>= 0.3.1), libmwaw-dev (>= 0.3.21)